Ratanasuwan, P., Nonphiaraj, S., Pongjanyakul, S., Somdee, W., & Taesiri, W. (2015). Efficacy of Combination of Ketamine and Morphine for Intravenous Patient Controlled- Analgesia in Upper Abdominal Surgery at Srinagarind Hospital. Srinagarind Medical Journal, 30(5), 67. Retrieved from https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/40017